1. Field of the Invention
The invention relates to an accessory apparatus on moving picture cameras for focusing information.
2. Description of the Prior Art
In general, a "shutter" is used for numbering film scenes and for the synchronous marking of the film camera and sound recording instrument. This "shutter" is comprised of a black board on which the number of the scene to be filmed is written in chalk. A ledge is affixed to the lower edge of the shutter by a hinge to enable it to be knocked against the board. The "shutter" is placed in front of the camera. On direction "sound away" and "picture away", the sound recording instrument and camera are started. Thus, the camera films the "shutter" with the number on it. Thereupon, the assistant announces the number for the sound, and the ledge at the lower edge of the board is knocked against the surface. The resultant knock is received by the sound recording instrument as the camera has filmed the event. The reason for this measure is that the number of the scene can be read in the projection or on the cutting table and can be heard simultaneously on the sound track and the scenes may be placed on the cutting table in case of sound-synchronized pictures, i.e. the optical signal of the picture sample (impact of the ledge on the lower edge of the shutter) and the acoustical signal (knock) on the perforated band may be brought into registry on the cutting table, which assures that in this scene the picture and sound will be synchronized.
The knocking of the shutter is replaced in some cases by a light shutter. In this case, a small light on the shutter is connected with the sound recording instrument. The sound recording master actuates the switch, the small light lights up and the sound track is marked simultaneously.
These shutter systems have various disadvantages.
The knocking of the shutter, including the direction, takes 10-15 sec. Another few seconds pass until the scene begins because the person operating the shutter must leave the picture. Furthermore, it is frequently necessary to turn or even to pivot.
Thus, solely for numbering the scene with this known "shutter knocking", about 8-10 meters of raw film is used up. In this manner, 10 to 25% of the entire raw film material needed is used up for shutter knocking. Furthermore, a special operator must be provided at the filming for the shutter knocking.